Clegg also rather ominously predicted “something’s got to give”.

The two-year time limit can, in theory, be extended although the unanimous consent of Westminster as well as the European Council, which is made up of 27 member state leaders, would be required.

Given Europe’s heavy political calendar, in which the key EU member states of both France and Germany have general elections scheduled, and European Parliament’s demands for time to be allowed to vote upon a potential deal, it appears the timeframe for the U.K. government is closer to 18 months rather than two years.

“There is a lot at stake and 18 months is actually a very short (amount of) time,” Hilary Benn, chair of the Brexit select committee, told CNBC on Wednesday.

“Being honest about the challenges is not being gloomy, it is doing our job as parliamentarians because this is a really, really important moment for the future of the country,” Benn added.